The present invention relates to connecting a multiconductor cable to electric circuit elements which are mounted on suitable carriers, and more particularly, the invention relates to solder connection between such a cable and prefabricated circuitry.
In the art of the printed circuitry a carrier element, such as a printed circuit board, provides a mounting structure for circuit modules or individual circuit elements. The need arises to provide external connection between the conducting lines on the board and other components outside of the printed circuit board. For this, it has been suggested to construct the art work of the printed circuit lines on such a carrier in such a manner that many or all such lines which require external connection end along one edge, and plug elements are clamped to that edge to make contact, on one hand, with these circuit lines, preferably in a releasable manner while permitting, on the other hand, engagement with counter plug elements from which a suitable cable connections or other connecting devices extend.
This particular mode of connection is disadvantaged by the fact that basically the resistance provided and established by the interface between the printed circuit lines on one hand and the contacting connector element, on the other hand, is not or at least insufficiently constant. Moreover, that particular resistance is predeterminable to a limited extent only and may vary as time progresses. This is particularly the case if the connecting network as a whole and cables involved in the overall connection, as well as the board, experience to some extent mechanical loads.
Alternatively, it has been suggested that the connecting circuit lines on such a board or other carrier, are provided with soldering vanes or soldering ears, permitting soldering of the individual conductors in the connecting circuit to the cable. Undoubtedly, this kind of arrangement results in well defined electrical resistances in the connection between the elements, and the portions of the resistances that include the solder points will not necessarily experience any load of, if it experiences mechanical loads, the electrical resistance will not change.
However, this arrangement is disadvantaged by the fact that, as experience has shown, the wires are soldered occasionally to the wrong vanes. In view of the large multitude of connections involved, it is most likely and has in fact been so observed that these incorrect connections are discovered only afterwards when the particular device is tested. Moreover, it was found that in the case of such an error it is not necessarily economical to make the requisite correction; rather it may be more advantageous to discard the faulty assembly. This, of course, is a relative aspect, and needless to say, these erroneous connections should be avoided, because they constitute a definite loss.